Apparatus for grinding and polishing lenses



June 17 I924.

J. E. STRECKER APPARATUS FOR (immune AND POLISHING LENSES Filed April 21. 1923 Patented June 17, 1924.

UNITED STATES JOHN E. STRECKER, 0F PHILADELPHIA, PENNSYLVANIA.

APPARATUS FOR GRINDING AND POLISHING LENSES.

Application filed April 21, 1923.

To all whom it may concern:

Be it known that 1, JOHN E. S'rRnoKnR, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented 'certain new and useful Improvements in Apparatus for Grinding and Polishing Lenses, of which the following is a specification, reference being had to the accompanyingdrawings.

This invention relates to apparatus for grinding and polishing lenses and more especially toric and meniscus and it is an object of the invention to provide a novel and improved apparatus of this general character to provide a revolving or oscillation of the lenses to be ground or polished together with means for imparting a rotary motion to the grinding lap and at the same time keeping said lap parallel with the plane of rotation or oscillation of the lenses.

Another object of the invention is to provide an apparatus of this general character whereby the lenses to be ground and polished are arranged concentric about the axis of the revolving or oscillating support whereby one of the desired curves is produced by such rotation or oscillation of the lenses and wherein the other curve produced by the tool or lap carried by an oscillatory support having movement at right angles to the direction of motion of the first named rotary or oscillatory support and whereby the tool or lap, while being rocked back and forth describing the radius of the toric curve, is caused to travel in concentric circular motion I in a manner whereby is avoided aberrations and irregularity of curve.

The invention consists in the details of construction and in the combination and arrangement of the several parts of my improved apparatus for grinding and polishing lenses whereby certain important advantages are attained and the device rendered simpler, less expensive and otherwise more convenient and advantageous for use, as will be hereinafter more fully set forth.

The novel features of my invention will hereinafter be definitely claimed.

In order that my invention may be the betterunderstood, I will now proceed to de scribe the same with reference to the accompanying drawings,- wherein :-V

Figure 1 is a view partly in elevation and partly in section illustrating an apparatus Serial No. 633,634.

constructed in accordance with an embodiment of my invention; 7

Figure 2 is a front elevational View of the structure as illustrated in Figure 1 Figure 3 is a fragmentary front eleva tional view illustrating certain of the parts in a second position;

Figure 4 is a detail sectional view taken substantially on the line 4-4 of Figure l; and

Figure 5 is a graphic view illustrating the relative paths of movement between the lenses and lap during operation of the ap paratus. e

As disclosed in the accompanying draw ings, the lenses 1 are cementedwor otherwise held to the support 2 herein disclosed as a' cylindrical support, said lenses 1- being dis posed eccentrically to the shaft or axis 3 for said support. One of the desiredcurves of the lenses may be described from the axis 3 of the support 2 and for which reason the radius chosen for said support must be in accordance with the desired curve of the lenses. v

The lap or tool 4 is provided to produce the other curve, said lap or tool 4 oscillating to a desired extent in a direction of the axis or shaft 3, the desired curve produced the lap or tool 4 being determined by the position of the center 5 of oscillation of said lap or tool 4. V x

As herein disclosed the center of oscillation 5 comprises a shaft upon which is mounted for requisite rocking movement a bracket 6 provided at its upper or outer portion with the laterally disposed arms 7 providing a support for the shaft 8. The lower end of the shaft 8 has extending longitudinally therefrom the pin 9 eccentric to the axial center of said shaft 8 and which is received within a pin or recess 10 provided in the axial center of the lap or tool 4 whereby said lap or tool 4 upon rotation of the shaft 8 is caused to travel in a circularorbit. The shaft 8 is adapted to be driven in any desired manner but through the medium of a means to allow for the desired oscillation of the bracket 6. The bracket 6 is to be oscillated as preferred while any desired means may be employed for driving the shaft or mandrel 3. The circularmotion of the tool or lap 4 is preferably either slightly less or greater than the peripheral speed of a support 2 or more particularly the lenses 1 mounted thereon.

Extending in opposite directions from the lap of tool 4: and in a direction parallel to the plane of rotation or oscillation of the support 2 are the arms 11, each of said arms extending between a pair of arms 12 depending from a head 14 positioned at an end of a frame F.

The lower portion of the shaft 8 extends through the frame F and the inner faces of the heads 14 are opposed to the arms 15 depending from the lower arm 7. Disposed through the heads 14L are the pivot members 16 which have operative engagement with the depending arms 15 whereby the frame F is supported for swinging or rocking movement in a direction parallel to the axis or I shaft 3.

As the lap or tool 4? is caused to travel in its circular movement by rotation of the shaft 8, the arms 11 working back and forth between the arms 12 allow for the desired motion in one direction while the swinging frame F permits the desired movement in V the other direction.

In practice, While the bracket 6 is rocking back and forth or oscillating to describe the radius of toric curve being made, the shaft 8 causes the lap or tool 4' to travel in con centric circular motion, the arms 11, which extend parallel with the plane of rotation ofthe support 2-or more particularly the lenses mounted thereon, allaberrations and irregularity of curve are removed.

The rotation or oscillation of the support 2 and the oscillation of the bracket 6 cause the tool or lap' l to travel in a zigzag path as indicated at a in Figure 5. This zigzag movement in itself will cause irregularities of curvatures but by causing the lap or tool 4: to'travel in circular motion as indicated at b in Figure 5 such irregularities are removed. This is due to the fact that as each time the bracket 6 carries the lap or tool 1 over the lenses 1 arranged on the support 2 the circular motion of the lap or tool t laps all parts that are produced by the zigzag motion. 7

It is to be understood that prior to applying the'lenses 1 to the support 2 said lenses may be shanked to shape and roughened to approximately the required curvatures.

From the foregoing description it is thought to be obvious that an apparatus for grinding and polishing lenses constructed in accordance with my invention is particularly well adapted for. use by reason of the convenience and'facility with which it may 7 v be assembledand operated, and it will also be obvious that my invention is susceptible of so me change and modification Without departing from the principles and spirit ing lenses con'iprising a rotatable support adapted to have lenses arranged on its periphery and disposed cireiunferentially thereof, a tool arranged in opposite relation to said support, an oscillatory support for said tool, and means for moving the tool in a circular path during the movement of the oscillatory support.

2. An apparatus for grinding and polishing lenses comprising a rotatable support adapted to have lenses arranged on its periphery and disposed circumferentially thereof, a tool arranged in opposite relation to said support, an oscillatory support for the tool, and means carried by the oscillatory support for moving the tool in a circular path during the movement of the oscillatory support.

3. An apparatus for grinding and polishing lenses comprising a rotatable support adapted to have lenses arranged on its perlphery and disposed circumferentially thereof, a tool arranged in opposite relation to said support, an oscillatory support for said tool, a shaft rotatably supported by the oscillatory support, means for rotating said shaft, said shaft being provided with a pin eccentric to its axis, said pin engaging the tool to cause the tool to travel in a circular path during the movementof the oscillatory support.

at. An apparatus for grinding and'poljshing lenses comprising a rotatable support adapted to have lenses arranged on its periphery and disposed circumferentially thereof, a tool arranged in. opposite relation to said support, an oscillatory support for said tool, a shaft rotatably supported by the oscillatory support, means for rotating said shaft, said shaft being provided with a pin eccentric to its axis, said pin engaging the tool to cause the tool to travel in a circular path during the movement of the oscillatory support, a frame, means for connecting the frame to the oscillatory frame for swinging movement, oppositely directed arms carried by the tool and disposed in a direction parallel to the plane of the first named support, and guide means carried by the frame with which the arms of the tool engage.

In testimony whereof I hereunto affix my signature.

JOHN E. STRECKER. 

